Flasher



H. R. GROSS Jan. s, ,1948.v

FLASHER .Filed April 8, 1945 3 Sheets-Sheet 2 Jan. s, 194s. H. GROSS `2,434,010

' FLASHER Filed April 8, 1945 l 3 sheets-sheets INVENTOR.

Patented Jan. 6, 1948 UNITED STATES PATENT OFFICEV FLASHER Henry R. Gross, Chicago, Ill.

Application April 8, 1943, Serial No, 482,252

10 Claims.

This invention relates to improvements in flashers, and more particularly to electromagneticaliy operated cyclic switches.

An object of `the invention is to provide a flasher and electric circuit, in which said flasher is adapted to be inserted to alter periodically the current supplied to a light source or other signal device associated therewith, so that it may be caused to ash or flicker.

Prior flashers have not been entirely satisfactory because relatively fragile; sensitive to variations in temperature or other atmospheric conditions; diicult to manufacture; of relatively high loss or breakagein manufacture; uncertain in operation; inconstant in periodicity of operation; slow in starting; and relatively high in cost. It is, accordingly, an important object of the invention to provide a flasher device of the character described which is rugged; not affected by variations in temperature or other atmospheric conditions; simple to manufacture; capable of manufacture with minimum loss and breakage; certain in operation; constant in periodicity of operation; quick starting under all conditions; and of relatively low cost.

Prior electromechanical, periodic or asher switches have not proved entirely satisfactory because they tend to stick between the instant that the circuit of the electric actuator is changed and the mechanical operator or linkage passes through the fixed midposition. It is accordingly a further object of the invention to provide an electromechanical flasher or periodic switch, wherein the switch contacts remain out of engagement during substantially the complete movement of the electric actuator in one direction. at which time they are moved into engagement and yet are not moved out of engagement until the electric actuator has substantially completed its movement in the opposite direction.

My invention contemplates an electromechanical flasher or switch in which relatively movable contacts may be caused toseparate as the electric actuator approaches its limited movement in one direction but will noty be returned into engagement until the electric actuator approaches the limit of its movement in the opposite direction.

It is a further object of the invention to provide an electromechanical switch operating flasher device, wherein the contact operating mechanism passes through spaced midpositions or dead centers as it moves successively in opposite directions, so that the circuit of the actuator may remain unchanged during the complete, or substantially complete, movement of the electric actuator in both directions.

A further object of the invention is to 'provide a flasher device of the above stated character, wherein the periodicity of flashing may be accurately and readily determinedor adjusted in the manufacture and use thereof.

Other and further objects and advantages of the invention will be apparent from the following description when taken in connection with the accompanying drawings, wherein- Figure 1 is a view in plan of a flasher embodying the invention, the housing thereof being removed;

Figures 1a, 2, and 2a are views similar to Figure 1, but showing the parts in different positions of operation;

Figure 3 is an enlarged, fragmentary view in side elevation of the flasher shown in Figure 1;

Figure 4 is a schematic diagram of a circuit incorporating the flasher shown in Figures 1 and 3;

Figure 5 is a view in plan of another form of fiasher embodying the invention, the housing thereof being removed;

30 Figures 5a, 6, and 6a are views similar to Figure 5 but showing the parts in different positions of operation;

Figure 7 is a schematic diagram of the circuit incorporating the flasher shown in Figures 5 35 and 6;

Figure 8 is a view partly in section of another form of flasher embodying the invention;

Figure 9 is an end view of the asher shown in Figure 8;

Figure 10 is a view similar to Figure 8 but showing the parts in a different position of operation;

Figure 11 is a view diagramming the Doperations of the flasher of Figure 8;

v Figure 12 is an exploded view in perspective of 4" certain parts of the flasher in Figures 8 and 11;

and t Figure 13 is a schematic diagram of the circuit incorporating the flasher shown in Figures 8 through 12. 0 Heretofore various types of periodic electric switches or ilashers have been developed, but those, generally speaking, have been unsatisfactory because of their fragility and/or speed of action. Usually those devices which are rugged are, in the case of thermoresponsive flashers, too slow in action, and, in other cases, too rapid in action. Various suggestions have been made to increase the speed of action of the thermoresponsive flashers and decrease the speed of action of the other types of flashers. However, in the case of thermoresponsive flashers, those which operate sufficiently rapidly are fragile and particularly sensitive to variations in temperature or.

other atmospheric conditions which cause a decrease or change in their speed of action, and, in some cases, changes in temperature or atmospheric conditions completely render the thermoresponsive flasher inoperative. A marked decrease in the rapidity of action of a flasher with changes in temperature or other weather conditions, creates great danger where the device is used to operate the turn signals of an automobile, for it often happens that, due to such decrease in the speed of action of the flasher, no turn signal is given before the turn is made or begun.' Thus, for example, thermoresponsive wires of sufllciently small diameter, i. e., seven ten-thousandths of an inch, which are sufllciently rapid in action under the most favorable conditions, are unsatisfactorily fragile and highly sensitive to changes in ambient temperature or other atmospheric conditions and become, under any but the most favorable conditions, dangerously slow in action.

Various suggestions have been made to decrease the speed of action of the other more rugged types of flashers by means of various mechanical operators or linkages, but which have not proved satisfactory because they tend to stick by changing the circuit to the electric actuator before the mechanical operator or linkage passes through its midposition or dead center in one direction or the other.

This invention contemplates the production of a asher rugged in all its parts, insensitive to changes in atmosphere or other atmospheric conditions, adapted to function quickly and with constant periodicity, and without sticking.

As shown in Figures 1 to 3 of the drawings, the ilasher 2 comprises a base 4 which may in some instances constitute the mounting bracket, or may be secured to a suitable mounting bracket of insulating material in other instances. A cover or housing (not shown) may be secured in any convenient manner to the base 4 or the insulating mounting bracket therefor.

The base 4 may comprise a length of strap iron provided at one end with a solenoid 6. The solenoid 6 may comprise the usual coil 8 wound or mounted upon a sleeve I of diamagnetic or nonmagnetic material such, for example, as brass closed at one end, as by a magnetic metal cap I0' soldered thereto. The sleeve is mounted on spaced magnetic plates i2 and I4, of which the plate i 2 may be formed integral with the strap 4, and the plate i4 secured to the strap as by screws I6, or the like, fastening the flange i8 to the strap I4. The sleeve I0 also forms a hollow guide for the movable core or plunger 20 of the solenoid.

The plunger 20 is, of course. Aof magnetic material and is moved in one direction, or to the left in the drawings, by the coil 8 when the same is energized, and in the opposite direction, when the coil is deenergized, by a spring 22 suitably fastened at one end to the plunger, and at the other end to a lug 24 upstanding from the base 4.

A switch 2l preferably comprises a disc 2s of insulating material pivoted as by pin or rivet 8l to a metal strap 32. The disc II has secured to, or inlaid in, its upper surface a generally semicircular contact segment I4. As shown in Pigure 3, this contact segment comprises a thin copper plate secured to the disc 24 by rivets 3l (Figure 2). A crank disc n, on which is formed a crank arm 32, is secured to the disc 2i by a rivet 4l. Spring contacts or wiper blades 42, 44, and 4l are secured at their enlarged outer ends to an insulating plate 4I secured to the strap by means including the rivet Il.

The blade 42 is of such length as always to engage the segment 24. while the blades 44 and 44 are of such lengths as to engage the segment 34 when the switch is in the position shown in Figure 2, but to engage the surface of the insulating disc when the switch is in the position shown in Figure 1. Themovement of the disc 2l is limited as by a pin Il upstanding from the plate 32 and received in aligned, peripheral notches I2 of the discs 28 and 32.

The mounting strap I2 may be formed integrally with a, generally Z-shaped bracket I4 having an inturned base flange Il slidably received between guide strips Us secured in any suitable manner to the base 4. 'I'he flange Il is provided with a slot to receive a screw I2 threaded into the base 4, the slot In permitting. upon the release of the screw B2, the adjustment of the bracket I4 and the switch 26 carried thereby toward and from the plunger 20. A suitable spring 84, preferably of generally U-shape and having one or imore convolutions BI. is secured at one end to a pin 68 carried at the outer end of the crank arm 39, and at the other end to a pin l0 of a lever or bellcrank 12 pivotally secured to the strap 32 as by rivet 14. The long arm 16 of the bellcrank is received in a. diametrical slot 1I in the plunger 2l, and is provided with an elongated slot 80 receiving a pin or key I2 extending perpendicularly to the slot 1l.

The pivot 'I4 for the bellcrank 12 is so positioned in relation to the pivot pin Ill of the crank disc Il that the pin 10, as the bellcrank swings, approaches the pin 48, thereby compressing the spring 44 until the pin 10, the pin 88, and the pivot pin 30 are in alinement, as shown in Figure 1a, after which the spring 64, in expanding, rotates the crank disc 3l and moves the disc 2l of the switch from the position shown in Figure 1 to the position shown in Figure 2. It should be noted that the ends of the spring 64 are received in annular grooves 84 and Il in the pins 88 and l0, so that the ends of the spring are movable angularly about these pins.

As exemplified in Figure 4, the flasher 2 may be connected in a circuit for flashing the turn signals of an automobile. Thus, the wiper blade 42 of the switch 28 and one endof the coil B may be connected internally of the flasher as by wires 8l and to a common terminal l2, which may project out of the housing represented by the dash line 94. The terminal 92 may be connected by a wire SI to the positive side of a battery II, or other source of electrical energy, which battery or source is grounded on the negative side as at IMI. The other end of the coil 8 and the wiper blade 4l of the switch 28 may be connected internally of the flasher housing to a common terminal |02 by wires iM and IUI. The wiper blade 44 may be connected internally of the flasher housing to a terminal |08 by wire ||0.

The terminal |02 may be connected by a. wire I2 to the movable blade ||4 of a turn signal control switch ||6, having xed contacts I|8 and |20. The contact I 8 may be connected by the common wire |22 land wires |24 and |26 in parallel to the iront and rear left turn signal lights |28 and |30, respectively. As is the lusual custom, the battery 88 being grounded as at |00, the` signal lights |28 and |30 may also be grounded as at I 32 and |34, respectively. The contact |20 is similarly connected by a common wire |36 and wires |38 and |40 in parallel to the front and rear right turn signal lights |42 and |44, respectively, which are also grounded as at |46 and |48, respectively.

The terminal |08 may, for the purpose of controlling an auxiliary load or signal, such as a pilot lamp |50, be connected to the load or lamp as by wire |52.

The operati-on of the device is as follows: Upon manual movement of the turn signal control switch blade I4 into engagement with one or the other of the fixed contacts of this switch, for example, the contact ||8, the circuit will be completed from the source or battery 88 through wire 86, to terminal 92, wire 90, solenoid coil 6, wire |04, terminal |02, wire ||2, switch blade 4, contact II8, and wires |22, |24 and |26 to the front and rear left turn signal lights |28 and |30. The' solenoid coil 8 is of such relatively high resistance that the current flowing through this circuit to the signal lights is insuillcient to energize the same fully or to the point of full incandescence or illumination. At the same time, the ampere turns of the solenoid coil are sufficient to create a. magnetic tleld for attracting or drawing in the plunger 20 against the action of the spring 22. As the plunger 20 moves inwardly, .the bellcrank ci' lever l2 is thereby swung in a clockwise direction from the position shown in Figure 1 through the position illustrated in Figure la, and to the position shown in Figure 2. When the pin l0 passes dead center position with relation to the pin 68, i. e., when the former passes the position of alinement with the pins 30 and 68 (Figure 1a) the spring 64, in expanding, rotates the switch 26 in a counter-clockwise direction, but the contact segment 34 of the switch does not connect the several wiper blades until the disc 32 has swung through a predetermined angle.

When the contact segment 34 connects the wiper blade 42 to the wiper blade 46, the solenoid 8 is shunted out of the circuit to the turn signal lights, to which a circuit is then completed from the battery 98, through wire 96, terminal 92, wire 88, blade 42, segment 34, blade 46, wire |06, terminal |02,Wire H2, switch blade I|4, contact I I8, and wires |22, |24, and |26 to the front and rear left turn signal lights |28 and |30. At the same time the circuit is completed. the pilot lamp |50 is connected .to the battery 88, through the wire 86, terminal 92, wire 88, blade 42, segment 34, blade 44, wire |I0, terminal v|06, and wire |52- the signal lamp |50 being, of course, grounded as The shunt established around the solenoid coil 8 by the wire 88, the blade 42, the segment 34, the blade 46, and the wire |06 effects the deenergization of the coil and the spring 22 pulls the plunger outwardly and rotates the bellcrank in a counterclockwise direction. When the pin I0 of the bellcrank moves past dead center position with the pin 68, as shown in Figure 2a, the spring 54 expands and moves the crank arm I8 in a required to move the switch di'sc 28 between itstwo limit positions shown in Figures l and 2. When the switch disc 28 has been moved to the full-line position shown in Figure 1, the wiper blades 44 and 48 are disconnected from the wiper blade 42, and the shunt circuit around the sole- 4noid coil is thereby broken; the coil is reenergized and the current through the signal leads, which are in series with the coil, is thereby reduced to cause the lights to flicker or flash. v

It will be observed that the mechanical linkage comprising the bellcrank or lever 12 and the crank 38-88 does not pass through a dead center position in either direction until the actuator has substantially completed its movement in either direction, and that the circuit to the actuator is not changed until the linkage has passed through dead center position in either direction; and further, that the dead center position of the linkage, as the actuator moves in one direction, is dinerent from the dead center position of the linkage as the actuator moves in the other direction. Hence, there is no opportunity for the switch to be moved to change the circuit to the actuator as the linkage approaches as fixed dead center position. Consequently there will be no tendency to stick, and the circuit to the actuator will remain unchanged until the switch has been shifted to one or the other o f its control positions.

Adjustment of the ilasher intervals, in manufacture and use. may be accomplished by loosening the screw B2 and sliding the bracket 54 inwardly or outwardly relative to the plunger 20.

Thus, if the bracket 54 is adjusted outwardly to increase the distance from the vertical plane through the axis of the plunger 20 and the pin 82 to the pin 14 as measured along a line perpendicular to such plane, the flashing interval will be increased because it will require a greater movement of the plunger 20 to effect the fixed angular motion of the bellcrank, whereas, if this distance is decreased, the hashing interval will also be decreased because then a lesser motion of the plunger 20 will eilect movement of the bellcrank through its ilxed angular distance. The ilasher would ordinarily be adjusted when used to llash turn signal lights to ilash at the rate of approximately sixty times per minute, but it may,

as above pointed out, be adjusted to ilash at other rates for the same or other uses.

As shown in Figures 5 to 7, the flasher 3 com- Prises a base 5 similar to the base 4 of the form o1' the invention shown in Figures 1 to 4, and on this base there is mounted a solenoid 1 similar to the solenoid 6 and similarly mounted. The solenoid 1 comprises a coil 8 wound or mounted on a sleeve |I of nonmagnetic or diamagnetic material, such as brass closed at one end. as by magnetic metal cap Il'. The' sleeve forms a guide for a plunger 2| of magnetic material. The plunger 2| is operated in one direction by the coil 8 and in the opposite direction by a spring 23 similar to the spring 22 of the rst form, and similarly fastened to the plunger and to a lug 25 upstanding from the base 5.

An auxiliary supporting block 21 of insulating material may be secured in any convenient manner to the base I so as to be positioned approximately at the elevation of the plunger 2|; thus. for example, the base may be formed with an integral ilange upstanding from one edge and provided with an outwardly turned edge 28 to which the block 1 may be secured as by screws or bolts 8|. The block 21 supports a combined switch and switch-operating linkage 88. This comprises a lever 85 pivoted intermediately its ends to the block 21 as by pin or rivet 81.

The lever 35 is made of electrically conducting material and on one side of the pivot carries a contact strip 4 I, and on the other side of the pivot is formed an arm or crank 48 extending perpendicularly from the lever 85. Movement of the lever 35 is limited by stops 45 and 41, which may consist of pins suitably secured to the block 21. The pin 41 limits the movement of the lever in a counter-clockwise direction, while the pin 45 limits the movement in a clockwise direction. The lever is urged in a counter-clockwise direction by a spring 48 fixed at one end to a pin 5| and bearing at its other end against the free end of the lever 35. The lever is provided with a small aperture 53 receiving the free end of the spring 49. The spring 48 is preferably formed with one or more central convolutions 55 increasing the resilience of the spring. The lever 85 is operated by the plunger 2| which, for that purpose, is provided with a pin 51 to engage the arm 43 which projects over the plunger 2|,

The switch contact 4| carried by the lever 85 cooperates with a switch contact 58 secured in electrically conducting relation to a metal lever 6| pivoted at its opposite end as by pin or rivet 83 to the block 21. The switch contact 4| also cooperates with a second contact 85 mounted on but insulated from the lever 5|. The lever 5| is moved in one direction or the other by a spring 61 secured to a pin 58 carried by the lever and to a fixed pin 1| carried by the block 21. The pins 69 and 1| are so positioned in relation to the pivot pin 83 that the spring will be moved from one to the other side of the pivot as the lever swings, and consequently, when it passes from one side to the other side of the pivot pin, it causes movement of the lever to its extreme position.

The lever 6| is formed with an integral arm 18 projecting perpendicularly therefrom and over the plunger 2| to engage and be operated bythe pin 51. A stop 13' limits the clockwise movement of lever 6|. The plunger may be provided with openings 15 to receive auxiliary pins similar to the pin 51, by means of which the stroke of the plunger required to operate the levers may be adjusted to adjust the flashing interval. natively, the pin 51 may have a head portion extending a substantial distance axially of the plunger and receive a set screw in either end surface, that may be adjusted inwardly or outwardly of the enlarged head to adjust the flasher interval in the same manner.

As shown in Figure '1, the flasher may be used to operate the turn signal lights of an automobile. Thus, as shown in this figure, the opposite ends of the coil may be connected internally of the flasher 3 by wires 11 and 18 to terminals 8| and 83, respectively. The terminal 8| may be connected by wire 85 to the positive side of a battery 81, 0r other source of electric energy, the negative side of which is grounded as at 88.

The terminal 83 may be connected by wire 8| to the movable blade 83 of a turn signal control switch 95, having also fixed contacts 91 and 88. The contact 91 may be connected by wire |0| and wires |03 and |05 in parallel to the left front and Alterrear signal lights |81 and |88 grounded as at ||I and ||8. The contact 88 may be connected by the wire ||5, and wires ||1 and H8 in parallel to the right front and rear signal lights |2| and |28 grounded as at |25 and |21. The contact 4I may be connected internally of the flasher as by The operation of this device is as follows: Upon I movement of the blade 88 of the turn signal control switch into engagement with one of its contacts 81 or 88, as, for example, contact 81, a circuit will be completed from the battery 81 through wire 85. terminal 8|, wire 11, solenoid coll 8, wire 18, terminal 88, wire 8|. blade 88, contact 81, and wires |0I, |08, and |05 to the signal lights |81 and |08. The solenoid coil 8, similarly to the solenoid coil 8 of the first form, is of relatively high resistance. so that the current flowing through this circuit is insufficient to energize the lights fully or to full incandescence. Therefore, the lights are unlit or only partially lit.

The solenoid coil being energized, attracts its armature 2| and moves it from the position shown in Figure 5 to the position shown in Figure 6. As the pin 51 moves to the left in the drawings from the position shown in Figure 5, the lever is rotated in a counter-clockwise direction by the spring 48 until it engages the stop 41 as shown in Figure 5a. When.the pin 51 engages the arm 18 of the lever 8|, it causes the lever to swing in a counter-clockwise direction until the pin 58 passes dead center with relation to pins 63 and 1| as shown in Figure 5a, and thereafter the spring. having thus been moved from above the pin 53 as indicated in Figure 5 to a position below the pin as indicated in Figure 6, causes the lever to snap to its limit of motion in the counter-clockwise direction, in which position the contacts 58 and 55 engage the common contact 4|. When this occurs, a direct connection is established between the terminals 8| and 83 in shunt to the coil 8. Hence. the coil is deenergized and current iiows directly to the signal lights from the battery, and also to the pilot lamp |88 in parallel to the main turn signal lights |81 and |08. The solenoid coil being deenergized, the plunger immediately begins to move to the right under the action of the spring 28. 'I'he lever 6| remains in the position shown in Figure 6, in which it is held by the spring 51, until the pin 51 engages the arm 48 of the lever 85 and causes the latter to swing in a clockwise direction. As the lever 85 swings in a clockwise direction, it causes the lever 5| also to move in a clockwise direction, but the contacts 4|. 58 and 55 remain in engagement during such movement of these levers and until the pin 58 passes dead center position with relation to the pins 88 and 1| as shown in Figure 6a. The spring 51 then moves above the pivot 53 as indicated in the drawings and snaps the lever 5| to its extreme position, in which its motion is limited as by the pin 18 secured to the block 21. When the switch blade 88 is moved to engage the fixed contact 88 similar actions occur to cause flashing or flickering of the right turn signal lights |2| and |23the pilot lamp |39 also flashing at the same time.

As shown in Figures 5 and 6, electrical connection between the wires |28 and 3| is preferably established by extending the wires beneath the 9 block 21 and soldering, or otherwise securing them to the lower ends of the pivot pins 81 and 63. respectively. .Electrical connection between the wire |33 and the contact 65 is preferably established through a lead which is suiliciently exible to accommodate the movement of the contact. It will be evident that the circuit to the solenoid or electric actuator remains unchanged during substantially the complete movement of the plunger 2| that the switch contacts remain in engagement during substantially the entire movement of the lever 35 by the pin 51; and that the lever 6| will be moved positively beyond the position in which the pin 69 is on dead center in relation to the pins 63 and 1| before the contacts 59 and 65 will be moved into engagement with the contact 8|. Consequently there will be no tendency for the iiasher to stick for the circuit to the actuator will not be changed until the linkage has passed definitely beyond dead center position, and the spring 61 has snapped the contacts out of or into engagement.

It should also be noted that since the levers 35 and 6| swing about spaced pivots, the contact 4| will exert a wiping action on the contacts. 69 and 65, thereby maintaining these contacts in good working order over a long period.

Either form of the invention will in operation indicate the condition of the lamps in the several circuits. Thus, ii one lamp of either set of turn signal lights burns out, the resistance in the circuit to that set of lights is increased, and this decreases the current flow through the solenoid coil, The plunger, therefore, moves at a much reduced rate. This is evidenced by the slower dashing of the pilot light, which thus provides an indication to the operator that one of the lamps in that set of turn signal lights has burned out.

' If both lamps of one set of Signal lights burnout,

then no current will flow through the solenoid coil, and hence the switch 26 will remain in the position shown in Figure 1 and the switch 33 in the position shown in Figure 5. Hence the pilot light will remain dark to thus indicate to the operator that both signal lights of that set are burned out.

Ii a partial short circuit occurs in either Set of signal lights, the current flowing through the solenoid will be increased, thus causing operation of the flasher at an increased speed, which will be evidenced by the more rapid flashing of the pilot light, thus apprising the operator of this fact. It may occur, that due to a partial short circuit, the rate ci flashing exceeds the persistence of vision and the pilot light may then appear to remain constantly illuminated, thus to indicate a partial short circuit .of some substantial magnitude. If a total short circuit occurs in either set, then a fuse or other circuit breaker, which, in accordance with conventional practice, may be inserted 'in the lead from the positive side of the battery to the asher, will break the Signal circuit 'and prevent damage to the elements thereof.

As shown in Figures 8 .through 13, the asher |56 comprises a cylindrical housing |58A of magnetic material, in'which is mounted a solenoid coil |80 surrounding a stationary cylinder |62 of brass or like material. One end of the housing lil is apertured to receive a magnetic plug |66 l 10 end of the plunger |66 is provided with one or more air passages or openings |10, by means of which the rate of movement of the plunger is predetermined. The operating pin |12 is secured to the closed end of the cap |14 of the plunger and is received in a guide slot |16 in the portion of the cylinder |62 extending beyond the ring |18 of ironv or other magnetic material, iltted in the open end of the housing |58 and encompassing the cylinder |62.

A contact carrier or blade |80 is mounted on, and insulated from, the ring |18 by suitable insulating spacers |82 and appropriate fastening means, such as screw |84.y The blade |80 carries a. stationary contact |86 which cooperates with a movable contact |88 ixed to an operating member |90.v The operating member |90 comprises a thin, resilient conducting metal strip slotted and shaped .to form an elongated portion |82 sprung out of the plane of the spring so that, upon application of pressure to such deformed portion, the strip is caused to snap from a. posis tion in which such deformed portion is bowed from one side of the strip to a position in which such portion is bowed from the other side of the strip. It will be evident further, that this togglelike spring strap will spring from one position to the other in response to the application of pressure to .the unsupported end of the strap.

As shown in Figures 8 and 10, this operating member or snapping spring strap carries the contact |88, and is secured to a terminal plate |94 f fastened as by rivet |96 to the insulating spacers cylinder |62 and a coil spring |66 inserted in the plunger engages the bottom of the cylinder |62 so as to move the plungeroutwardly when the solenoid coil is deenergized. The outer, closed A lever |98 pivoted as by pin 200 to a bracket 202 may be secured to, or formed integrally with, the terminal |94. The lever |98 is formed with a curved end 204, which extends over the slot |18 in the cylinder |62 adjacent the outer end of the slot so as to be engaged by the pin |12. The other end of the lever is rounded to provide a cam surface 206 engageable with the bowed portion |92 of the snapping spring strap |90. The lever is so mounted in relation to the strap that, upon movement in a, clockwise direction, as seen in Figures 8, 10, and 11, it depresses the bowed portion |92 toward the plane of the strap, and so causes it to snap from contact closing position to contact opening position.

Supply leads 208 and 2|0 are connected, respectively, to the switch blade and the terminal plate |95. It will be evident, upon energization of the solenoid coil |60, that the hollow plunger |66, which is of magnetic material, will be pulled inwardly of the cylinder |62 and, in so moving,

. compress the spring |68. On inward movement of this plunger and as it approaches its innermost position, the pin |12 engages the free end ofthe snapr spring strap and moves the body of the strap toward the now inwardly bowed portion |92 until the bowed portion snaps from one side to the other of the .strap and Vthereby snaps the strap carried contact |88 into engagement with the stationary contact |86.v On engagement of these contacts the solenoid coil ls shunted, as will later be described,` and the solenoid coil being thus deenergized, thespring |68 expands and moves the plunger outwardly of the cylinder |62 until, as thel plunger approaches the limit of its outward movement, it engages the hook end 20| and vswings lthe' lever in a clockwise direction, so that the lcam surface 206 of the lever presses inwardly upon the'bowed portion |92,so that that portion passing the plane of the strap tends to automati- 11 cally become bowed in the opposite direction and thus snaps the contact |88 away from the stationary contact |88.

The outward movement of the plunger may be limited by a lug or protuberance 2 i2 formed from the outer edge of the cylinder |62 and the counterclockwise movement of the lever |88 is limited as by a similarly formed lug 2H struck from the bracket 202. Thus, it will be seen that, when the, contacts are in open position, the pin |12 engages the strap and moves the same past dead center with respect to the bowed portion |82. while this bowed portion extends inwardly of the strap, as shown in Figures 8 and 11, and that the contacts are moved from closed to open position by moving .the bowed portion past dead center position with respect to the strap, as in the second diagram of Figure l1. The strap then snaps into 'its innermost contact closing position. It should be noted that this dead center position of the members past which the strap must be moved to effect closing of the switch, is different from the dead center position, as in the fourth diagram of Figure 1-, and past which the portion |92 must be moved to restore the contacts to open position. Hence, the contacts can never be stuck in either open or closed position, for the plane portion of the strap is snapped to a position changing the circuit only after the plane portion of the strap and the bowed portion of the strap have already been moved beyond one of the dead center positions.

As shown in Figure 13, the iiasher when used to operate the turn signal lights of an automobile, may have its lead 208 connected as by wire 2li to the positive side of a battery or other source 2|8 grounded as at 220. The lead 2|I of the asher may be connected as by wire 222 to the switch blade 224 of a single pole, double-throw switch having contacts 226 and 228 connected, respectively, to the left turn signal lights 238 and 232 and the right turn signal lights 234 and 238 in the manner previously described with reference to Figures 4 and 7. It will be evident that, upon closing of the contacts |88 and |88, the solenoid coil |60 will be deenergized and the signal lights supplied directly from the battery,

Since the contacts |86 and |88 are open whenever the solenoid coil is deenergized, a grounded pilot light 238 may be connected as by wire 24| to the strap |90 so that, whenever the contacts |88 and |88 are in engagement to thereby supply the signal lights with enough current to illuminate the same, a suiiicient current will be supplied to the pilot light 238. It will be evident, f course, that this pilot light will be illuminated whenever either the left or right set of the turn signals are operating. It; will be clear also, in respect to the asher shown in Figures 8 through 13, as with the flashers in Figures 1 through '1, that the increase of current ow through the solenoid, due to the burning out of one of the signal lights, will cause the flasher to operate at a slower rate, which will be revealed by the pilot signal, and that, if both lights of a set burn out, no current will ow through the solenoid coil when the same is connected to that set of lights so that -in that case the pilot signal will remain deenergized, thus indicating that the set of lights has burned out.

It is thought that the invention and numerous of its attendant advantages will be understood from the foregoing illustrative description, and it is obvious that numerous changes may be made in the form, construction, and arrangement of the several parts without departing from the spirit or scope of the invention or sacrificing any of its attendant advantages, the form herein described being a preferred embodiment for the purpose of illustrating the invention.

What I claim is:

1. A ilasher switch unit comprising, an electric actuator, a pair of flasher switch contacts for controlling the energization and deenergization of said actuator and a load circuit, and a switch operator, said operator having a plurality of dead center positions past which it is moved by said actuator, and means for making and breaking the switch contacts only upon movement of the operator past one of said dead center positions whereby to maintain the circuit to the actuator unchanged during the movement oi the actuator.

2. A flasher switch unit comprising, a solenoid, a plunger operated in one direction by said solenoid when the solenoid is energized, and means for operating the plunger in the opposite direction when the solenoid is deenergized, a flasher control switch, said switch being in circuit with said solenoid and comprising switch members relatively movable between circuit making and breaking positions to control the energization of said solenoid and a load circuit, said switch members being constructed to maintain the circuit unchanged during a predetermined relative shifting of said members, means for operating said switch members and including a mechanical linkage having a lost motion connection to said plunger to initiate relative movement oi' said switch members as the plunger approaches a limit of movement in either direction, and means for thereafter continuing the relative movement of said switch members to a limiting position changing the circuit of said solenoid.

3. A flasher switch unit comprising, a solenoid, a. plunger movable in one direction by said solenoid when the latter is energized, means for moving the plunger in an opposite direction when the solenoid is decnergized, a pair of terminals, iiasher switch means adapted periodically to connect and disconnect said terminals, said switch means comprising switch members controlling the alternate energization and deenergization of said solenoid, and a member operating said switch members and having an initial movement in which the relation of said switch members are maintained and a final movement changing the relation of said switch members to thereby change the circuit of said solenoidl means providing a lost motion connection between said plunger and said operator for initiating movement of said operator as the plunger approaches its limit of movement in one direction or the other, and means for continuing the movement of said operator once the same has been initiated.

4. In a ilasher, a solenoid, a. plunger moved by said solenoid in one direction upon energization of the solenoid, means for moving the plunger in the opposite direction upon deenergization of the solenoid, a switch having-a pair of contact: connected to opposite ends of the solenoid to shunt the solenoid from the circuit when said contacts are in engagement, load terminals connected to said contacts, means connecting said switch to said plunger for initiating movement of said switch 'as the plunger approaches a limit of movement in either direction, said switch being constructed to maintain the relation of said contac unchanged during initial movement of said switch, and means for automatically continuing the movement of said switch to change the relation between said contacts thereby to control the energization and deenergization of said solenoid.

5. A flasher switch unit comprising, a solenoid, a plungeroperated in one direction by said solenoid when the latter is energized, means for moving said plunger. in the opposite direction when the solenoid is deenergized, a pair of terminals, said solenoid being connected to said terminals, a switch comprising a shiftable contact blade connected to one end of the solenoid, a fixed contact blade connected to the other end of the solenoid whereby to establish a shunt circuit across the solenoid when the contact blades are in engagement, a lever for shifting said shiftable contact blade, a second lever having a lost motion connection to said plunger, and a spring interconnecting said two levers at points adapted to move past dead center with relation to -the pivot of the first lever as the second lever is moved by the plunger whereby energy is storedin the spring during the movement of the second lever to dead center position and utilized to shift the iirst lever as the dead center position is passed, the movable switch blade being constructed to have a predetermined movement relative to the xed blade before changing the engaging or disengaging relation of the blades whereby sticking of the levers about dead center is precluded.

6. A iiasher switch unit comprising, a solenoid,

a plunger operated in one direction by said solenoid when the latter is energized, means for moving said plunger in the opposite directiony when the solenoid is deenerglzed, a pair of terminals, said solenoid being connected to said terminals, a switch comprising a shiftable Acontact blade connected to one end of the solenoid, a ilxed contact blade connected to the other end of the solenoid whereby to establish a shunt circuit across the solenoid when the contact blades are in engagement, a lever for shifting said shiftable contactblade, a second lever having a lost motion connection to said plunger, a spring interconnecting said two levers at points adapted to move past dead center with relation to the Divot of the iirst lever as the second lever is moved by the plunger whereby energy is stored in the spring during the movement of the second lever to dead center position and utilized to shift the first lever as the dead center position is passed, the movable switch blade being constructed to have a predetermined movement relative tothe fixed blade before changing the engaging or disengaging relation of the blades whereby sticking of the levers about dead center is precluded, and adjustable means for determining the extent of lost motion in the connection between said second lever and said plunger for adjustably determining the periodicity of operation of the flasher.

7. A flasher switch unit comprising, a solenoid, a plunger moved by the solenoid in one direction when the latter is energized, means for moving the plunger in an opposite direction when the solenoid is deenergized, a pair of terminals, said solenoid being connected to said terminals, a first lever, a second lever, a switch comprising a contact carried by the rst lever and a cooperating contact carried by the second lever, means for normally maintaining the iirst lever in a predetermined position, aA spring -controlled toggle connection to the second lever for moving the second lever to one or the other of its extreme positions when the second lever has been moved a predetermined distance, the contact carried by the second lever being out of engagement with 14 v the contact carried by the ilrst lever when the second lever is in one of its extreme positions and in engagement with the contact carried by the iirst lever when the second lever is in its other extreme position, means operated by the plunger for moving said iirst lever against the action of said maintaining means to initiate movement of the second lever while maintaining said contacts Ain engagement, said spring controlled toggle moving the second lever relative to the first to move the contacts out of engagement when the levers have completed their predetermined movement, and means operated by the plunger for initiating movement o! said second lever` in the opposite direction, said spring controlled toggle thereafter moving said second lever to its initial 4position in which the contacts are in engagement.

8. In a iiasher, a solenoid,-a plunger moved by the solenoid in one direction when the solenoid is energized, means for moving the plunger in an opposite direction when the solenoid is deenergzed, a spring strap, said strap having a bowed portion deflectable relative to the remaining portion of the strap and adapted when compressed toward the remaining portion of the strap to snap the latter from one position to another and to be snapped by said strap from one position to another upon deflection of the remaining portion of the strap toward the bowed portion, a. pair of cooperating switch contacts adapted to be engaged and disengaged by the snapping of the spring strap as the bowed portion and the remaining portion of the strap are alternately deected, and means operatively connected to the plunger for alternately deiiecting the bowed portion of the strap and the remaining portion of the strap as the plunger approaches its limit of movement iirst in one direction and then in the other.

9. In a flasher, a solenoid, a non-magnetic cylindrical core, a hollow magnetic plunger mounted in said cylinder and movable inwardly thereof upon energization of the solenoid, spring means in said plunger and said cylinder forlmoving the plunger outwardly of the cylinder upon deenergization of the cylinder, said cylinder having a longitudinally extending slot therein, an operating pin carried by said plunger and movable along said slot, a stationary switch contact, a toggle spring strap carrying a switch contact for cooperation with said stationary contact, said operating pin being adapted to engage a portion of said strap for snapping the contact carried tb ereby into engagement with the stationary contact as the plunger approaches its limit of movement in one direction, and lever means engaging another portion of the strap and positioned for operation by the pin to snap the contact carried by the strap out of engagement with the stationary contact as the plunger approaches its limit of 4movement in the opposite direction, said contacts being connected to said solenoid to de'- termine the energization and deenergization thereof.

10. In a asher, a solenoid, a plunger moved by'said solenoid in one direction upon energizetion of the solenoid, means for moving the plunger in the opposite direction upon deenergization of the solenoid, a pair of switch contacts connected to the opposite ends of the solenoid and to load terminals to shunt the solenoid from the circuit when said contacts are in engagement and to change the voltage between the terminals as the contacts are opened and closed,

:,ssgovo switch operating means operated by the plunger, said switch operating means including spring means maintaining the relative positions of the contacts during movement of the plunger, and means for rendering said spring means effective to change the relative positions of the contacts as the plunger reaches its limits oi movement whereby to maintain the circuit to the solenoid unchanged during movement of the plunger in either direction.

HENRY R. GROSS.

REFERENCES crrnn The following references are of recordin the me of this patent-1 UNITED STATES PATENTS Number Name Date Plumtree Apr. 8, V1902 Numbe McMaster Nov. 3, 1942 

